Scirocco Register

The tank has rust in, again.
So yeah, it's probably my own fault for not finding a plastic fuel neck. I had my tank out about two years ago, cleaned and re-welded.
Is there anything i can do instead of this job again or am i going to have to face up to it and just get the tank sorted and then prevent things happening again? Someone mentioned chucking powerful magnets in on here before, does this actually work? The rust as far as i could tell shouldn't be magnetic.

I think that the principal of the magnet is that whilst rust itself isn't magnetic, the detritus that collects in your tank is mostly incompletely oxidised steel, so at least some of each fragment will still be magnetic. In practice, it's difficult to be totally thorough and removing/cleaning the tank like you did is the best solution. However, you also need to replace the filler neck at the same time as that is usually where most of the debris is coming from. You can get a new one from VW that will be an exact fit, or you can try to find a decent second had one, or modify a mk1 Golf or BMW (3-series, I think) plastic one.